1. Field of the Invention
This invention relates in general to syringes and, in particular, to a measurer for dispensing accurate dosages from a syringe.
2. Summary of the Prior Art
Syringes are in common use for dispensing fluid into the body of an individual or animal. A syringe typically includes a cylindrical chamber or barrel having a plunger for ejecting a predetermined dosage through an extended hollow needle. The chamber may be calibrated by indicia to provide an external volume indication of the fluid in the barrel or chamber.
Conventional syringes are difficult to use by visually impaired individuals. A correct dosage is critical when administering medications, such as, insulin for diabetics. A visually impaired person may have great difficulty in accurately determining the volume of insulin or other medication in the syringe barrel. The use of an incorrect amount of medication can be harmful to the health of the individual who is self administering the dosage using a syringe.
Attempts to safely control the amount of fluid delivered by a syringe have not been satisfactory in the past. For example, the syringe disclosed in U.S. Pat. No. 3,749,284 employs a relatively complex calibrator strip assembly which is not practical for use by a visually impaired person. In U.S. Pat. No. 4,252,159, another complex dosage device is shown which controls the amount of medication withdrawn into the barrel before injection. Accordingly, it is desirable to provide an improved and safe technique by which a visually impaired individual can alone inject accurate dosages of medication with a syringe.